Archive for July, 2010
A US company has taken the “do-it-yourself” concept to a completely new level – the firm is selling kits to build and fly small satellites for as much as 8,000 dollars.
Randa and Roderick Milliron, a Mojave, Calif.-based couple, are the brains behind the program they’ve named TubeSat. The duo have been developing a bare-bones, low-cost rocket system for the last 14 years.
The first of four suborbital test flights is slated for August and there are customers for those as well.
“The acceptance and enthusiasm has been overwhelming,” Discovery News quoted Randa Milliron, chief executive of Interorbital Systems, as saying.
The customers include hobbyists and universities, including the Naval Postgraduate School in California, Morehead State University in Kentucky, and the University of Sydney in Australia.
“There’s been a massive number of shelved experiments, caused by a dearth of low-cost launch systems. This is an opportunity for the academic community to fly affordably,” Milliron said.
Interorbital’s rocket, the Neptune, will place up to 32 TubeSats and 10 slightly larger off-the-shelf spacecraft called CubeSats into orbit about 192 miles above Earth.
Launches will take place from the island of ‘Eua, located in the Kingdom of Tonga, in the South Pacific. (ANI)
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A Nasa satellite was temporarily blinded after the brightest explosion of a star ever witnessed in space, officials admitted.
The space agency’s orbiting Swift observatory was overwhelmed by glare from the eruption, called a gamma-ray burst.
Such was the power of the last month’s blast that the observatory’s software ignored it as if it were an anomaly.
Scientists at Nasa’s Goddard Space Flight Centre, in Maryland, said the explosion of X-rays that followed came from a star that died five billion years ago, far beyond our own Milky Way galaxy.
Experts say the timing meant the blast, which astronomers believe was caused by a star collapsing to form a black hole, occurred before the Sun and planets formed.
When a star explodes, radiation travels at the speed of light in all directions. Gamma rays reach Earth first, followed by X-rays.
Light from the flare-up, titled GRB 100621A, reached Earth on June 21 after it had travelled nearly halfway across the universe.
It then hit the satellite, which formed in 2005 to observe the sky with X-ray style eyes.
Observing gamma-ray bursts is one of the satellite’s prime objectives but it was not built to cope with such an intensely bright blast.
“The intensity of these X-rays was unexpected and unprecedented,” said Neil Gehrels, Swift’s principal investigator.
“Just when we were beginning to think that we had seen everything that gamma-ray bursts could throw at us, this burst came along to challenge our assumptions about how powerful their X-ray emissions can be.”
Dr Phil Evans, of Leicester University’s space department, added: “The burst was so bright when it first erupted that our data-analysis software shut down.
“So many photons were bombarding the detector each second that it just couldn’t count them quickly enough.
“It was like trying to use a rain gauge and a bucket to measure the flow rate of a tsunami. This burst is one for the record books.”
When the telescope recovered, Dr Evans and colleagues were able to measure that the distant explosion had been 140 times brighter than the brightest steady source of X-rays, a neutron star 500,000 times closer to Earth.
Professor David Burrows, of Penn State University, who is lead scientist for Swift’s X-ray Telescope (XRT), said: “This gamma-ray burst is by far the brightest light source ever seen in X-ray wavelengths at cosmological distances.”
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Australia’s NBN Co. is making an A$1 billion ($88.4 million) bet on satellite broadband as it plans to invest in two Ka-band satellites designed to deliver high-speed services across Australia. That’s a part of the government-backed company’s plan to connect the entire sunburned country (with apologies to Bill Bryson) with broadband. The vast majority of services (90%) will be offered via fiber-based services while the remaining 10% will come from next-generation satellite and wireless technologies.
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The so-called Galaxy 15 zombie satellite that lost contact with ground controllers on Earth in April is still adrift in space, with engineers keeping a close eye on the wayward satellite as it approaches two other spacecraft this month.
The Galaxy 15 satellite is currently drifting along a stable and predictable path, according to its communications satellite fleet operator Intelsat. The main focus now is preventing Galaxy 15 from interfering with other nearby satellites, including two of Intelsat’s own, though no collisions are expected.
“The overall goal is to minimize disruption,” Steve Good, Intelsat’s global director of customer solutions engineering, told SPACE.com. “It’s in all of our best interests to minimize any disruption.”
The company is preparing several techniques to mitigate potential signal interference as Galaxy 15 is set to fly by two other Intelsat satellites this month: Galaxy 13 and Galaxy 14.
The 4,171-pound (1,892-kg) Galaxy 15 satellite went rogue on April 5, when it stopped responding to controllers on the ground.
Yet, while the satellite veered from its assigned orbital slot of 133 degrees west longitude, 36,000 kilometers over the equator, the “zombie satellite” maintained an active payload, with its C-band telecommunications still functioning.
Interference from Galaxy 15′s stuck-on signal is the main concern, since the chance of it actually crashing into other satellites is remote to non-existent, Intelsat officials have said.
Not quite in the clear
On Thursday, July 8, Galaxy 15 is expected to begin approaching Galaxy 13, making its closest pass on July 13.
“Galaxy 15 has a very large inclination, and if it stayed there, that would be great,” Good said, referring to the tilt of the satellite’s orbit with respect to Earth’s equator. “But, twice a day it crosses the zero longitude line. At that point in time, that’s when the physical distance between the two satellites is going to be minimized.”
Intelsat’s Galaxy 13 and Galaxy 14 satellites both provide video media services to U.S. customers, and the satellite operator has been in regular contact with users in preparation for the flybys.
“We’re looking at each customer specifically,” Good said. “We’re working with them and we’ve offered them options. We’ve been in talks almost daily.”
Galaxy 15 will begin entering Galaxy 14′s orbit on July 26. It will make its closest pass on July 30.
Intelsat engineers have planned a variety of techniques to address interference concerns from Galaxy 15, including boosting the sensitivity of satellites the zombiesat flies near, and moving them if necessary. They are also arranging for some customers who uplink to Galaxy 13 or 14 services to shift – or “mispoint” – their antennas, depending on the location of the rogue satellite, so they don’t receive its wayward signals.
“If you have a large antenna, for example, you can mispoint to the east, and as soon as Galaxy 15 passes, you then mispoint to the west,” Good explained. “It’s like you’re intentionally avoiding the Galaxy 15 satellite.”
In addition, while each case is different, Good and his team can look to their successful collaboration with SES as inspiration.
In May, the satellite operator SES World Skies, whose AMC-11 satellite orbited into Galaxy 15′s cross-hairs, worked with Intelsat to successfully perform a series of intricate maneuvers in order to avoid interference and service interruptions.
“Not all flybys are created equal, but we certainly learned a lot of lessons from the first one,” he said.
Intelsat will also be able to use this knowledge to tackle similar circumstances in the future.
The company will next work closely with Telesat, a satellite services provider headquartered in Ottawa, Canada, since Galaxy 15 is expected to swoop near Telesat’s Anik F3 satellite, following the Galaxy 13 and 14 encounters.
A mind of its own
Several attempts to shut down Galaxy 15 have been unsuccessful, leaving the defunct satellite drifting in the cosmos.
“Normally when an anomaly occurs, the satellite just stops working and we don’t have to worry about it,” Good said. “Galaxy 15 is still operational, so in this case, the satellite is still “functioning” in a deterministic state. But, we know exactly where it is, we know what it’s doing, and we know the settings of the satellite.”
Galaxy 15 launched on Oct. 13, 2005 aboard an Ariane rocket. Its manufacturer, Orbital Sciences Corp. of Virginia, has said that an intense solar storm in early April may have caused the breakdown in communication.
Meanwhile, Intelsat has launched an on-going technical investigation, but has yet to reach any definitive conclusions as to the cause of the glitch.
Such an anomaly, however, is unprecedented, said Good.
“This is definitely a unique situation,” he said. “There are people who have worked here for over 40 years who have not seen such a thing.”
The future of zombiesat
Eventually, Galaxy 15 is expected to lose its Earth-pointing capability. Once this lock on Earth is lost and its solar panels are no longer pointed at the sun, the satellite’s battery power will eventually die.
“When the battery power decreases past a certain threshold, the payload will shut off,” Good explained. “It will no longer receive and transmit, and its batteries will continue to deplete.”
The satellite could also reach a threshold that causes its onboard computers to reset, said Good, but the possibility of this happening is still unknown.
“There is a possibility that the onboard computer could reset, but we don’t know what that probability is,” he said. “Still, there is a chance. It would almost be like a “control-alt-delete” on your computer. It would begin sending telemetry again. It would wake up and realize ‘What am I doing here?’”
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Biking on JetBlue: Versus and JetBlue have teamed up to offer live coverage of the 2010 Tour de France on JetBlue flights. That’s in addition to the 36 channelsof live DIRECTV programming offered via the JetBlue personal seatback televisions.
Junk Watch: How bad is that space junk problem? Bad enough that the U.S. Air Force plans to launch a new satellite to track all orbiting objects. The Space-Based Space Surveillance satellite is scheduled to launch on July 8 from Vandenberg Air Force Base, CA.
Airborne Broadband: ViaSat’s airborne satellite-broadband network for the U.S. military now offers high-resultuion video and broadband data at speeds up to 1 Mbps.
Quote of the Week: From Denver Post TV critic Joanne Ostrow on that Comcast rebranding – “We’ll still think of them as Comcast, of course, because XFinity is not only confusing, but it make us wonder what they’re trying to hide by inventing a new handle? Sort of like Blackwater rebranding as Xe.”
Disney Games: Disney has a new mobile games developer as Tapulous becomes part of the Disney Interactive Media Group. Tapulous founders Bart Decrem and Andrew Lacy and their development team are along for the ride.
Canal+: Interesting times at Canal+ as 20% stake holder Lagardere Group says it will launch an IPO to sell its shares after talks with Vivendi failed.
Mediaset v. Sky: More price cutting wars abroad as Italy’s Mediaset intros price cuts on its DTT pay package to help counter recent cuts from Sky Italia
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